1. Field of Invention
The invention relates to a belt device that supports an endless belt with a support roller, an image forming apparatus provided with the belt device, and an endless belt.
2. Description of Related Art
There exists an image forming apparatus that includes a belt device that transports a recording medium on an endless belt inside the image forming apparatus. As disclosed in, for example, Japanese Laid-Open Patent Publication No. 2000-337464, a belt device includes a protrusion that is provided on an inner surface of an endless belt with the protrusion extending along a running direction of the endless belt. The protrusion prevents the endless belt from being out of position while the endless belt is running.
However, in the belt device, the protrusion formed on the endless belt runs onto a support roller supporting the endless belt while the endless belt is running. To solve such a problem, in the belt device disclosed in Japanese Laid-Open Patent Publication No. 2000-337464, a resin tape is applied to a surface of the endless belt opposite the projection at a position near the projection to prevent the endless belt from readily deforming and the projection from running onto the support roller. However, as the tape is applied to the endless belt, a step is formed on a surface of the endless belt where an object to be conveyed, such as a recording medium, contacts the endless belt. The step will possibly cause an adverse effect on the conveyance of the object.